Unitary engine compressor



Feb. 12, 1946. l.. E. FowLl-:R

` UNITARY ENGINE cMPREssoR Filed Dec. 4, 1944 a WM/M W2 f. 2 M M e Patented lFel). 12, 1946 UNITED ,STATESI PATENT OFFICE Leonard E. Fowler, Detroit, Mich. Application December 4,1944, Serial No. 566,615

Claims.

This invention relates to engine compressor umts, that is to structures oi' the type in which an engine and an air compressor are built as a single unit employing a common crankshaft, the

principal object'beingthe provision of a simple and eillcient unit of the character described.

Objects of the invention include 'the provision of an engine compressor unit in which the engine is of the two-stroke type and of unusually great power for its size; the provision of a unit of the type described in which the cylinders of the engine and compressor unit are so constructed and arranged as to be capable of delivering an unusually large amount of'combustible mixture, or air to form thel same, to the combustion chamber of the engine; thefprovision of a, construction as above described in which the inward movementof the pistons oi' bothithe engine and the compressor is utilized to compress a combustible mixture, or at least air for a combustile mixture, in the crankcase of the device for delivery to the combustion chamber of the engine; the provision of a construction as above described inbeing so constructed and arranged as to draw air for vsupporting a combustible mixture, ora combustible mixture, into the crankcase of the engine upon outward movement of both the pis-v tons in their respective cylinders and acting to compress such air or combustible mixture upon inward movement of the pistons in the cylinders, whereby to provide a means for delivering, when necessary, an unusually large charge to the combustion chamber ofthe engine, such charge being of greater volume for a corresponding pressure than the swept volume of the piston in the engine cylinder only.

The above being among the present invention, the same consists in certain novel features of construction and combinations of parts to be hereinafter described with-reference to the accompanying drawing, and then claimed, havingv the above and other objects in view.

In the accompanying drawing which illustrates suitable embodiments of the present invention, and in which like numerals refer to like parts throughout the several diierent views,

Fig. 1 is a vertical sectional view taken longitudinally through an engine compressor unit conyobjects of uney sructed in accordance withthe present invent on;

Fig. 2 is a partially broken, horizontal sectional view taken centrally through the engine shown in Fig. 1; and,

Fig. 3 is a fragmentary view of a modied form of the engineshown in Fig. 1 and taken in the -same plane as the view in Fig. 1.

The principal object of the present invention is the Provision of an engine compressor unit capable of being constructed in any desired size but particularly adapted for small size units, which is unusuallyt economical to manufacture and is unusuallyeiiicient in operation. To that end it employs anl engine oflthe two-cycle type particularly because of the economy in the cost of manufacture thereof. lThe compressor is of a conventional type preferably having a piston of the' same bore as the engine and arranged with its cylinder in approximately opposed relationship with respect to the engine cylinder and having a base or crankcase common with the engine cylinder; The outer end of the compressionA cylinder only is employed for air compressor function and Ithe inner end of the air compressor is open to the crankcase or base common to both v it and the engine cylinder. A crankshaft having opposed throws is provided in the base or cranklcase with one throw connected to the engine piston, and the other throw connected to the compressor piston so that the pistons of both the compressor and engine move outwardly and inwardly substantially simultaneously with one another in their respectivevcylinders.

The engine is of the type employing base compression so that as both the engine andcompressor pistons move outwardly in their respective. cylinders a suction is created in the base or crankcase which is employed for drawing a combustible mixture thereinto, or at least air for supporting a combustible mixture, and when the pistons of both compressor and engine move inwardly toward one another such combustible mixture or air is compressed and at a'desired point in the stroke of the engine is delivered to the combustion chamber thereof in whole or in part. y

It will be appreciated from the above description that in accordance with the present invention a construction is provided in which the movement of the compressor piston in its cylinder is not only employed for the purpose of compressing air to be employed' for some useful purpose other than operating the engine itself but it is further employed for increasing the charge which 2l l is capableof being delivered to the engine cylinder and through which the compressor is actuated, the increased charge thus capable of being delivered to the engine cylinder and which at least in some respects has a superchar'ging effect on the engine, enables the engine to deliver a be drawn into the base or crankcase and charged with fuel therein as, for instance,in themanner disclosed and claimed in vmy Letters Patent of the United States No. 1,986,630 issued January l, 1935, on Internal 'combustion engine, or the charging of the air with fuel may be withheld until the charge of air is being fed from the crank' case to the combustion chamber or until it has been introduced into the combustion chamber, at which time the charge of fuel may be injected into the air in accordance with any one of a number of conventional fuel injector devices. However, for the purpose of simplicity in descrip tion it will be assumed in the illustrated embodiment that'the air flowing into the engine is first passed through a carburetor and, therefore, is

' in the formof a combustible mixture during passage from the lcarburetor to the-engine and through the engine to the .combustion chamber thereof, this being by way of explanation and not by way of limitation.

It will also be appreciated that while in the drawing a unit having a single engine cylinder and a single compressorcylinder Iis illustrated,

that multiples of these units may be constructedA employing av common crankcase and a commoncrankshait, the mainl necessity in such case being that the base portion of the crankcase for each individual cylinder be sealed from open communication lwith the base portion for eachother engine cylinder 'in accordance withgwell under-` stood two-cycle practice. A

Referring now to the drawing and particularly to Figs. 1 and 2 it will be understood that the device comprises'a base or crankcase III to one side of which is suitably fixed an engine cylinder I2 andv to the opposite slde'of which is iixed a compressor cylinder I4, the cylinders I2 and I4 being approximately diametrically opposed to each other withV respect to the Iaxis of the crankshaft I8 rotatably mounted within the crankcase i8 and both cylinders I2 and I4 opening freely into the crankcase Il, Preferably and as shown, forreasons of running balance,the cylinders I2 24 is reciprocably mounted in the engine cylinder I2 and connected to its corresponding connecting rod 22 by a conventional piston pin 28. A piston 28 is reciprocably mounted in the compressor cylinder I4 and connected to its corresponding connecting rod 22 by means of a pistonv pin 88.

Where as is usually desirable, the pistons 24 and 28 are of the same diameter, the same weight, and the piston pins are arranged with their axes at the same distance from the axis of rotation ofthe crankshaft I8 so that the pistons 24 and 28 have the same stroke in their respective cylinders, as is usually desirable but not necessary, thenthe reciprocating forces of the pistons and connecting rods on opposite sides of the crankshaft axis balance themselves out as will be appreciated, thus resulting in a smoother running mechanism.

The head of the compressor cylinder I4 is provided with an air inlet connection indicated generally at 82 embodying a suitable valve mechanism permitting flow of air therethrough only in the direction of to the cylinder I4 and is provided with a similar connection Indicated generally at 84 provided with a suitable valve mechanism permitting flow of air therethrough only in the direction of from the cylinder I4. These valve mechanisms are, therefore, generally in thev nature of aV check valve each including, in the movement of the particular structure shown by way of example,l a ball valve l88 and a cooperating spring 88 constantly urging it towards its seat, the ball valve for the inlet valve opening inwardly towards theV cylinder upon a suction being exerted in the cylinder I4 between the piston 28 and the head of the cylinder during inward movement of the -I piston 28, and closing under the force of its corresponding spring 88 and the pressure of the air compressed in the cylinder I4 during outward piston 28. Under the latter conditions the pressure of the air .built up in the cylinder I4 between the piston 28 and the head l of the cylinder exerted on the valve 88 of the connection 84 will cause the valve 88 to raise against the force of the spring 88 and. permit the escape of the compressed air out through the connection 84 to a suitable pointof storage or use.

While any suitable or conventional method of introducing combustible mixture, or air for forming the sanne, into the base or crankcase III may be employed, that shown by way of illustration is the conventional third port system in which the cylinder I2 is .provided withla conventional inlet port 40.,.norma1ly closed bythe piston 24 but uncovered by the piston 24 when the latter approaches the outer limit of its travel in the cylinder I2. In the present case and as previously mentioned a carburetor indicated generally is shown connected to the intake e 4I by means of a tubular'connection I4 in which a conventional butterfly type of throttle valve 48 is and I4 are of the same bore and the pistons which operate therein have the same stroke and weight.

The crankshaft I8 is provided with main jour-` nals I8 having/suitable bearing in the vend walls of the crankcase I8 and diametrically opposed crank pins 20jwhich are preferably oilset from one another axially of the crankcase as shown. As brought out in Fig. 2 the engine cylinder I2 is preferably centrally aligned with one of the crank pins 20, while the compressor cylinder I4 is preferably centrally aligned with the other crank pin 28, this for the purpose of enabling straight connecting rods to be employed. A conventional two-cycle type of slanting head piston positioned to enable conventional control of the volume of combustible mixture being fed to the engine and, therefore, to control the speed of the engine. It will be appreciated that when the port 48 is opened by the piston 24 the carburetor 42 is in opencommunication past the throttle valve 48 with that portion vof both cylinders I2 and vI4 inwardly of their correspondingpstons 24 and 28 and with the interior of the crankcase III.

' In accordance with conventional two-cycle practice the base orcrankcase I8 is provided with an outlet port 88 which is connected by a tube 82 with a port 84 opening onto the bore of the cylinder I2. The port 84 is so positioned in the length er the cylinder lz that when the pieten 24 approac s the inner limit oi' its movement in the cylinder 2 the piston 24 will uncover the port 54. At the salme time the piston 24 will uncover the exhaust port 56 which discharges into an exhaust be appreciated that as thel tional mechanism than is required in providing a simple engine compressor unit. It will also be.

appreciated that the ability to deliver a greater volume of combustible mixture to the combustion chamber of the engine cylinders enables arelatively greater power output to be obtained from the' engine portion of th device than would otherwise be capable of being obtained in conventional cylinders I2 and I4 inwardly of their corresponde ing pistons 24 and 28. The suction thus createdwill be as a result of the displacement of 'both pistons 24 and 28 outwardly in their corresponding cylinders instead of merely by the displacement of one cylinder outwardly in` its cylinder as occurs in conventional two-cycle engines oi' the base compression type. This suction inthe crankcase I0 vwill increase until the piston 24 reaches substantially the position illustrated in Fig. 1 during such outward movement at which time vthe piston 24 will begin to uncover the port 40 and thus permit the flow of air through the carburetor and port 40 to the crankcase I0 and those portions of the cylinders I2 and I4 inwardly oi their corresponding pistons. This ow will usually continue until the -crankpins 20 have passed dead center position and the piston 24 has returned on its inward stroke to substantially the position illustrated in Fig. 1 at which time it again closes the port 40. At this time the crankcase` I 0 and the inner ends of the cylinders I2 and I4 are lled with the maximum amount of combustible mixture capable under the particular degree of opening of the throttle valve 48 then prevailing and as the pistons 24 and 28 continue theirinward movements toward each other they will act to compress the combustible mixture thus drawn into the crankcase III and inner ends of the cylinders I2 and I4. This compresslonwill continue until the piston 24-has moved inwardly a suiliclent amount to. permit its upper lend to uncover the port 54V which thereby providesa substantiallv free passagefor the flow of the compressed combustible mixture from the base I 0 constructions of the same size.

This added charge capable of beingdelivered to the combustion chamber or the engine may be likened to a supercharging effect which, as is well recognized, is capable of materially increasing the maximum power output or an internal combustion engine. Where a more positive action in this respect is desired resort may be. had to a modiiled form of two-cycle engine wherein mechanically operated valve means other than the piston is employed for controlling the flow of combustible mixture, or air for providing a combustible mixture, to the engine cylinder, one

form `of which is illustratedinFig. 3.y

In Fig. 3 the only change from the construction shown in Figs. 1 and 2 is in the last-mentioned connection and, therefore, only these changes will be described, it being understood that the remaining partoi' the structure will be identical to that shown and described inv Figs. 1 and 2. Those parts of Fig. 3 identical to those shown in Figs. 1 and 2 are indicated by the same numerals and do not require further description.

The cylinder I2' in Fig. 31s substantially 'the y same as the cylinder I2 shown in Figs. 1 and 2 except that the port 54 is eliminated and instead f' the cylinder I2 is provided with an axially di rected port 10 in its head which port is connected by the tube 52 with the port 50 in the base Il).l

The port 10 is controlled by a poppet valve 12 constantly y urged towards closed position by meansof a coil spring 14. vIt is operated against the force of thespring 14 by means of a rocker shaft I 6 by means of a pairof gears 88 opera-` tively connected to both. The contour of the cam 84 obviously may be such as to control the opening and closingbf the valve 12 at any desired inte combustion chamber s2 provided in the cuter end of the cylinder I2 outwardly of the head of the piston 24. Any previously burned charge of combustible mixture inthe combustion chamber 62 will simultaneouslyfescape out the exhaust port 56 to the manifold 58. In this respect it will be appreciated the exhaust passage 58 may be so constructed and arranged as showny as to be opened slightly in advance of opening of the port 54 in accordance with conventional practice.

It will be appreciated from the above that movement of the piston 28 in the cylinder I4 not only serves to draw air into, compress, and discharge air kfrom the outer end of the cylinder I4 to provide a suitable supply of compressed air for any useful purpose, vbut additionally that the movement of the piston 28 in the cylinder I4 further provides a means whereby a greater amount of combustible mixture, or air for forming a combustible mixture charge, is capable of being delivered to the combustion chamber of the engine cylinder than in conventional two-cycle types of construction, and this without adding any addi- -when a port such as 54 controlled by movement of the engine piston, as shown in Figs. 1 and 2,

is employed. It will be appreciated nby changingv the contour of the cam 84 the point of opening u and closing the valve 12v may be varied and the flow of combustible'mixture to `the combustion chamber 62 may be continued even after the exhaust port '56 has been closed by the piston 24. The piston 24 in this case may be a fiat top piston as shown in Fig. .3 instead Aof the conventional slanting head piston as illustrated in Figs. land 2 and, of course, as illustrated in Fig. 3 the spark plug 60' requires rthat it be shifted out of'the` position illustrated in Figs. l and 2 in order to accommodate the valve 12.

Other conventional forms of two-cycle engine structurs may, of course, be employed in place of the specic lconstruction shown without departing from the spirit of the present invention as long as the feature of 'employing the movement of both the engine andcompressor pistons for drawing in combustible mixture, or air for forming the combustible mixture, into the crankcase and there compressing it for delivery to the combustion chamber of the engine cylinder, is employed.

What I claim is:

1. In an engine compressor unit, in combination, a crankcase, a crankshaft having approximately dlametrically opposed crank pins rotatably mounted in said crankcase, a cylinder secured to said crankcase and projectingtherefrom in approximately radial relation with respect to the axis of rotation `oi.' said crankshaft, a second cylinder fixed to said crankcase and projecting therefrom in approximately radial relation with respect to the axis of rotation of said crankshaft and in approximately dlametrically Opposed relation with respect to the mst-mentioned cylinder, a piston reciprocably received in each' of said cylinders, a connecting rod connecting one of said pistons to one of said pins, a connecting rod connecting the other of said pistons with the remaining of said pins, a head for each of said v cylinders,v means for introducing air into one of Said cylinders between the head thereof and the piston therein underthe iniluence of a suction created between said head and piston during inward travel of the piston therein and blocking the escape of air from said cylinder therethrough, meansvfor dischargingv air compressed in said' one of said cylinders between said head thereof and the said pistons therein during outward move-` ment of the said pistons therein and blocking the return flow of air therethrough, means for intro- 'dcing air into said crankcase under a suction created therein by outward movement of both said pistons in their corresponding cylinders, said other of said cylinders having an exhaust port formed therein controlled by movement of the corresponding piston therein and provided for the escape of burned products of combustion from said other of said cylinders between the head thereof andthe corresponding piston therein, said other of said cylinders having another port therein arranged for open communication with the bore of said first-mentioned cylinder between said head thereof and the corresponding vpiston therein whensaid piston has approached Ithe inner limit of its movement in said other of said cylinders, and means formingan open passageway between said other port and said crankcase for delivery of fluid compressed in said crankc'ase by inward movement of said pistons in their corresponding said cylinders.

2. An engine compressor unit comprising, in combination, a crankcase, a crankshaft rotatable in said crankcase, a pair of approximately diametrically opposed cylinders fixed and sealed to said crankease, av piston reciprocable in each of said cylinders, said crankshaft having approximately dlametrically opposed crank pins, a connecting rod connecting one of said-pistons to one A crankcase, a pair of one-way valve mechanisms of said crank pins, a connecting rod connecting the other of said pistons to the other said crank pin, the inner ends of said cylinders being in open communication with the interior of said crankcase, a pair of one-way valve mechanisms associated with 'one of said cylinders operable to in troduce air into said cylinder `between the head thereof and the piston therein under the influence of a suction created by the inward movement of said piston therein and' for discharging air compressed therein'by'outward movement of said piston therein, means associated with said ing outward movement thereof in said cylinders ing inward movement 'of said pistons in said third port therein adapted to be uncovered b y the ytravel therein, and a passageway connecting said whereby fluid compressed in said crankcase by asomo-i y 'engine for introducing air into said crankcase during movement of said pistons toward the outer limitv of their strokes, the other of said cylinders having an exhaust port therein adapted to be uncovered by the piston therein when said piston therein approaches the inner end oi its stroke therein, the combined displacement of both oi' said pistons in their corresponding cylinders during outward movement thereof in said cylinders serving to create a suction in said crankcase for drawing air thereinto through said means, said air being compressed by the combined displacement of both said pistons in their respective cylinders during inward movement of said pistons in said cylinders. and means for delivering said compressed fluid to said other of said cylinders when the corresponding piston therein appreaches the inner limit of its stroke.

3. lAn engine compressor unit comprising, in combination, a crankcase, a crankshaft rotatable in said crankcase, a pair of approximately diametrically opposed cylinders n xed and sealed to said crankcase, a piston reciprocable in each of said cylinders. said crankshaft having approximately dlametrically opposed crank pins, a. connecting rod connecting one of said pistons to one of said crank pins, a connecting rod connecting the other of said pistons -to the other said crank pin, the inner ends of said cylinders being in l open communication with the interior of said associated with one of said cylinders operable to introduce air into said cylinder between the head thereof and the corresponding piston therein under the influence of a suction created therein by the inward movement of said corresponding piston therein and for discharging air compressed therein by outward movement of the corresponding piston therein, means associated with said engine for introducing air into said crankcase during movement oi' said pistons toward the outer having Van exhaust port therein adapted to b'e uncovered by the piston therein when said piston therein approaches the inner end of its stroke therein, the combined displacement of both of said pistons in their corresponding cylinders durserving to-create a suction in said crankcase for drawing airl through said means thereinto, said air being compressed by the combined displacement of both said'pistons in said cylinders durcylinders, said other of said cylinders having a corresponding o f said pistons when said corresponding piston approaches the inner limit of its third port .with the interior of said erankcase the combined displacement of. said pistons during their inward travel in their corresponding said cylinders is discharged into said other of said cylinders between the corresponding piston therein and the head thereof when said correspending' piston therein approaches the inner limit of its stroke therein.

4. An engine compressor unit comprising, i combination, a crankcase,.a crankshaft rotatabl in said crankcase, apair of approximately di ametrically opposed cylinders fixed and sealed t said crankcase, a piston reciprocable in each o said cylinders, said crankshaft having approxi mately dlametrically opposed crank pins, a con 'necting rod connecting one of said pistons to on of said crank pins, a connecting rod connecting the other of said pistons to the other said crank pin, the inner ends of said cylinders being in open communication with the interior oi said'crankcase, a pair of one-way valve mechanisms associated with one of said cylinders operable to introduce air into said cylinder between the head thereof and the piston therein under the influence of a suction created therein by the inward movement of said piston therein and for discharging air com- Dressed therein by outward movement of the piston therein, means associated with said engine for introducing air into said crankcase during movement of said pistons toward the outer limit of their strokes, the other of said cylinders having an exhaust port therein adapted to be uncovered by the piston therein when said piston therein approaches the inner end of its stroke therein, the combined displacement of both of said pistons in their corresponding cylinders during outward movement thereof in said cylinders serving to create a suction in said crankcase for drawing air through said means, said air being compressed by the combined displacement of both said pistons in said cylinders during inward movement of said pistons in said cylinders, said other of 'said cylinders having a third port therein, passage forming means connecting said third port with the interior of said crankcase, a valve controlling the opening and closing of said third port, and means for operating said valve in timed crankcase in radial relation thereto, a piston in each of said cylinders, means operatively connecting each of said pistons to said crankshaft, the construction and arrangement of said cylinders and crankshaft being such that said pistons will move inwardly in their respective cylinders approximately ysimultaneously and outwardly in their respective cylinders approximately simultaneously, the inner ends of said cylinders being in open communication with the interior of said crankcase, a pair 0f one-way valve mechanisms associated with one of said` cylinders operable to v introduce air into said cylinder between the head thereof and the piston therein under the iniiuence of a suction created by the inward moverrent of said piston therein and for discharging air compressed therein by outward movement of said piston therein, means associated with said engine for introducing air into said `crankcase during movement of said pistons toward the outer limit of their strokes, the other of said cylinders having an exhaust port therein adapted to be uncovered by the piston therein when said piston therein approaches the inner end of its stroke therein, substantially the combined displacement of both of said pistons in their corresponding cylinders during outward movement thereof in vsaid cylinders serving to create a suction in said crankcase for drawing air therelnto through said means, said air being compressed by substantially the combined displacement of both said pistons in their respective cylinders during inward movement of said pistons in said cylinders. and means for delivering said compressed fluid to said other of said cylinders when the corresponding piston therein approaches the inner limit of its stroke.

LEONARD E. roWLERf 

